jmortensen

Cheapest route would probably be to get a whole diff and tear it down for the spiders. If you're lucky you might find someone who just installed an LSD and still has the open carrier. Might check on Hybrid Z since I would guess there are more LSD installs going on over there...

Good analysis of the Stage III. It really is not an aggressive camshaft.

Actually that sounds perfectly normal. There should be lash in the gears. Running them without any lash will soon create a whole bunch of lash. Also, when you turn the halfshafts you're also involving the gears in the carrier, which would have nothing to do with a clunk that you'd hear when shifting. Backlash should be measured at the ring gear, not at the halfshafts and not at the pinion. I wouldn't replace a quiet, extremely low mileage R180 with a junkyard R180. Think of it this way: what is the likelihood that the diff you bought has LESS miles on it than the one you're pulling out? Next to nil. I personally have had zero luck trying to feel for a bad halfshaft U-joint with the shaft in the car. I have to take them out to have any chance of feeling a bad U-joint. If this is an early 71 with the diff moved forward relative to the later cars, that would make it even more likely to be a U-joint issue. U-joint problems were the reason that they moved the diff back in the later cars.

http://forums.hybridz.org/showthread.php?t=111523

You have an unusually low amount of mechanical advance for an early Z distributor. I don't know the exact spec, but memory tells me they're supposed to have something like 22 or 24 degrees of mechanical advance. I would disassemble the distributor all the way down and make sure that it isn't all gunked up, clean and lube everything, and reset the timing. I'm not sure how much vacuum advance you should have, but your total mechanical advance is not enough in my opinion, especially if you drive in low vacuum situations a lot (if you're a leadfoot). Checking backlash via the pinion is not the right way to do it. I would suspect that there is nothing at all wrong with your diff, as the slop is greatly magnified when you check at the pinion due to the cut of the pinion gear teeth. If you have a clunk check the normal issues: front diff mount, mustache bar bushings, driveshaft bolts, U-joints, splines on the stub axles. If you want to check backlash correctly you'll need to pull the diff and the rear cover, and check it at the ring gear.

$3-4K isn't enough money to really build a good L6 if you're not doing all the labor yourself. You might try to find a built-up engine for sale.

Eibach sells progressive springs, and that's what is pictured. It is true that there are hillbillies out there that will lower their vehicles by taking a torch to the spring, but that's not what we're looking at here. In terms of the spring function, yes, if the coils are bound then they aren't doing anything. But when you're actually driving the suspension doesn't just compress, it also extends as the wheels go down into depressions in the road, etc, and when this happens those springs will open up a bit and that will lessen the spring rate for the first part of the travel. If the coils didn't bind at some point, then your spring wouldn't be "progressive". It would just be a lighter weight spring.

Arne is correct. As I originally stated, it won't make much of a difference at all (I too doubt you would be able to notice it), but technically, those are upside down. I probably shouldn't even have mentioned it, but it's a bit of a pet peeve of mine.

The top half of a spring is sprung weight, and the bottom is unsprung weight. When you install the spring with the bound coils down, you increase the unsprung weight, which is bad. They should be installed with the bound coils on top, regardless of how Eibach is printed on them. Similar case with the halfshafts. The heavy part should be attached to the diff, the light part should attach to the wheel, for the same reason.

Those are probably the Tokico springs. Search that and you'll see similar threads...

Search and you'll find that those are progressive springs, and what you see there is normal for a progressive spring. Yours are installed upside down, but that really doesn't make any difference in the ride.

The carrier can be swapped.

The stock oil pressure gauge is notoriously inaccurate. If you want to find out for sure what is going on, you can check it against a cheap mechanical gauge. There are aftermarket suppliers for parts like the oil pump, but I'm sure you could go down to the dealer and pay 2-3 times what the aftermarket part costs if that's your preference. You might check out Black Dragon Auto and Motorsport Auto, they are the two biggest parts suppliers for the Z. Arizona Z Car had the best deal on a high volume oil pump when I bought mine about 10 years ago. Adjusting the valves is not difficult and sounds like it needs doing. The early cars didn't come with sway bars in the US. The aftermarket bars included new uprights for the rear suspension and located the bar behind the diff. This is fine (preferred even), provided there is no rubbing. My guess is that the end links used were too long, and this is the cause of the rubbing. If you get a Suspension Techniques bar for the rear of a 240 it also mounts behind the diff and may even be a direct replacment. If you took a couple photos we should be able to identify it for you. 240-260-280Z and 280ZX engines are all interchangeable. The 260Z engine is basically a boat anchor and the 280Z and ZX are fuel injected. The carbs from your 240 will bolt straight onto a 280 engine though and it gives you a nice displacement bump. If you search around you might find an 80-83ZX like I did to source the engine, transmission (close ratio 5 speed) and larger diff with lower gearing. You need a couple more parts to get that R200 diff installed from a 280Z, but it's well worth it in my opinion. You might be able to download the Factory Service Manual (FSM) from www.carfiche.com. It is very thorough and better than the Haynes or similar manuals, although they would be helpful too if you don't have any reference material at all.

Install the trans, use a tape measure to find the distance from the pivot to the center of the hole in the console. Make a 90 degree bend there as tight as possible, leave the top of the stick long and then cut to desired length with a cutoff wheel or hacksaw and put a generic shift knob on it that doesn't require threads, a la MOMO. That's what I'd do if I had it to do again. If the bend is too tight I'm sure you could massage it back out a bit in a vise. If you use a truck shifter then drill a new pivot hole higher than the first. Doesn't need to be a lot higher, just enough to keep the shifter from hitting the trans. Your 83 trans should have plenty of room to drill on the ears.

Just as a counter point to the above, I drove my Z with triple 44's, L28 with ~8.5:1 compression, cam, light flywheel, ACT clutch, header and 2.5 exhaust in stop and go and never had any trouble at all. That should be a horrible combo for traffic, but it really easy to drive. I got low mid 20's on the highway. My friend had a 510 with an L16 and 44's, cam, flywheel, clutch, etc, and it was damn near impossible to drive. The extra torque and mass of the long crank make the L6 much easier to deal with.

I'm having a hard time believing that a mechanic would do this. IME the Z rotors don't usually come off the hub too easily, so it really is something to be avoided if at all possible. Normally to turn a Z rotor a mechanic would remove the wheel bearings and wipe out the grease from the hub, then turn the rotors with the hub on the lathe, then repack the bearings and reinstall in the hub and reinstall the hub and rotor on the car. Is that not what happened on your brake job? The way you wrote that out made me think that you thought repacking the bearings was necessary due to the removal of the rotor from the hub, which is not the case.

It would be more work to separate the rotor from the hub to turn it. I've never seen it done, although I suppose you might run across a particularly stupid mechanic or a lathe that is missing the correct adapter for the hub bearings I guess...

On a Z the rotor gets bolted to the hub, so when you put it in a lathe you use the hub and it's all bolted together. So you basically get the same effect. Most newer cars have slip on rotors. On that type of setup the on car lathe has a real advantage. It is true however that most brake lathe spindles are bent because stupid mechanics slam down heavy drums and rotors on them (I know because I used to be a stupid mechanic who didn't realize the damage this caused), so the on the car lathe might be better in that respect. If you had a straight spindle on the brake lathe though, there should be no real difference between doing it on the car vs off the car for a bolt on rotor like a Z has.

How about banning this spammer???

I don't know much about street pads. I'd say stay away from Metal Masters as I had a warpage issue with them on two different vehicles, but that's about the best I can do.

Having put many many rotors on a lathe and actually SEEN the cutter hit one side of the rotor and not the opposite side, and seen it reversed 180 degrees awawy on the rotor, I'm a bit perplexed by this whole "deposit on the rotor" scenario. That said I also have all of Carroll Smith's books, and I'd consider myself a fan of his. Whether you call it a deposit or a warp, cutting the rotor on a lathe will indeed remove the problem. Unfortunately it will also make the rotor thinner, and more likely to develop the same problem quicker the next time in my experience. Having passed the ASE test on brakes, I can tell you that they don't subscribe to the deposit on the rotors theory, or at least they didn't when I took the test in the early 90's. So telling an ASE certified mechanic that there is no such thing as a warped rotor is an exercise in futility, and to keep going to different shops telling them that there is no such thing is about as useful as repeatedly slamming your head into a wall. To fix the problem use different pads. Whether the pads are depositing material on the rotor or warping it is irrelevant. Using a different pad is going to be the solution. You can either cut the rotors or replace them. I made a decision not to turn rotors on my own vehicles a while back, so I just replace them, but cutting will work.

The one with more hp should "spin up quicker". The one with a longer stroke might very well have a lower rpm limit or redline. If your L24 spins up quicker than your L28, it's most likely due to the L28 not being tuned correctly. This subject used to come up all the time at hybridz, with people saying that a 327 revs faster than a 383. Built "the same" this is not true.

Tire balance, wheel bearings, ball joints, tie rod ends, or something loose. Ball joints and tie rod ends are pretty much guaranteed bad if they haven't been replaced in the last 10 years or so, and people often overlook them. Tire balance is surprisingly hard to get right it seems, it's something that many shops do a horrible job at. Probably has to do with the lowest man on the totem pole doing the tire mounts and balances. Also people have an affinity for the wheels which have no lip on the outer edge to hold wheel weights and they don't like the stick on weights because they're ugly. You need weights on the inside AND outside of the wheel to dynamically balance a tire.

I cut mine out to install a fuel cell in a race car. It was from a 70, and like yours was basically rust free. I had one guy mention in passing that he might want it, but never actually sold it. Even though the well is a rust prone part of the car, I don't think you'll have too much luck selling it, and re-engineering the tank just to run duals seems like a big PITA to me. I believe the BRE's ran the duals under the stock tank. From my own experience I can say that installing a 12 gal fuel cell adds about 20 lbs to the car vs the stock tank. The stock tank is LIGHT compared to most other options, although a new car plastic tank may save a lb or two.

There is no one good answer. You should use the resources you have available and search here and at hybridz.org. Then read for a couple weeks. After that, you should have a better idea of the questions you should be asking, and with more specific questions we can give you more specific answers.